using System;
using System.Collections.Generic;
using System.Linq;

public class Program 
{
    public static void Main(System.String[] args) 
    {
       var x = int.Parse(Console.ReadLine());
       var y = int.Parse(Console.ReadLine());
       var maxMove = int.Parse(Console.ReadLine());
       var orderCnt = 0;
       var rotCnt = 0;

       if (y == 0) rotCnt = 1;
       if (y > 0 && x != 0) rotCnt = 1;
       if (y < 0 && x != 0) rotCnt = 3;
           
        var move_x = Math.Abs(x / maxMove);        
        var move_y = Math.Abs(y / maxMove);
        var div_x = x % maxMove;
        var div_y = y % maxMove;

        if ( maxMove < div_x ) move_x += div_x / maxMove;
        else move_x += div_x;

        if ( maxMove < div_y ) move_y += div_y / maxMove;
        else move_y += div_y;

        orderCnt = (move_x + move_y + rotCnt);
        Console.WriteLine(orderCnt);
    }
}